1. Technical Field
The invention relates to valves. Particularly, the invention relates to a valve assembly for a dual-component cartridge containing two materials which are to be mixed together and dispensed. More particularly, the invention relates to an add-on valve assembly which removably mounts to a nozzle of the cartridge for controlling the flow of the materials from the cartridge and which is removed from the nozzle after use for cleaning and disposing of any material remaining in the valve assembly after the materials have been emptied from the cartridge.
2. Background Information
Various types of material cartridges have been developed which store two separate materials, such as chemically reactive resins or resins and a hardener, which materials must be maintained out of contact with each other within the cartridge. These cartridges are typically formed with two separate chambers, each chamber storing one of the reactive materials. These chambers are formed in the cartridge in various configurations. For example, the chambers may be formed in a side-by-side relationship within the cartridge whereby the materials are positioned adjacent one another and separated by a thin wall formed integrally with the cartridge housing. The materials flow through respective passageways formed in a valve member and nozzle of the cartridge and are mixed by a motionless mixing tube upon exiting the nozzle.
In another example of a dual-component cartridge, the chambers are formed coaxially within the cartridge. One of the materials is stored within a cylindrical inner chamber and the other material is stored within an annular outer chamber. The material passageway of the inner chamber is off-center allowing the passageways to be formed adjacent one another within a single nozzle.
In a further example of a dual-component material cartridge, the chambers may be formed either side by side or coaxially. One of the materials is stored within one of the chambers while the other material is stored within a sausage or chubb which is inserted within the empty chamber of the side-by-side cartridge or within the inner chamber of the coaxial cartridge. When pressure is applied to the chubb, the thin flexible film which encloses the material ruptures allowing the materials to be dispensed from the cartridge.
As previously mentioned, these dual-component material cartridges have a nozzle and valve member formed integrally with the outer housing of the cartridge. The nozzle and valve member are formed with a pair of passageways through which the separate materials flow when being dispensed. When the materials are dispensed they flow through the separate passageways into some type of mixing tube where they are thoroughly mixed before being applied to an application surface.
One type of valve member which can be formed on the material cartridge is shown in U.S. Pat. No. 4,846,373 which discloses an apparatus for proportioning or for proportioning and mixing plural different fluid compositions. A neck is formed integrally with and extends forwardly from the cartridge housing and is formed with a pair of passageways each of which communicates with one of the material chambers of the housing. An opening is formed between a threaded nozzle of the cartridge and the neck for receiving a valve stem. The valve stem is formed with two holes which rotate to communicate with the passageways of the neck and nozzle when the valve stem is in the open position, and which rotate perpendicular to the passageways of the neck and nozzle when the valve stem is in the closed position. A motionless mixing tube may threadably engage the nozzle to mix and dispense the materials.
Although this valve member is adequate for the purpose for which it is intended, forming the valve integrally with the cartridge causes disposal problems when the cartridge is emptied and is to be discarded by the user. The pressure mechanism which forces the materials from the cartridge extends only up to a front wall of the cartridge and thus does not completely evacuate the passageways of the neck, valve member and nozzle of the cartridge leaving a residual amount of material therein. Occasionally, these material cartridges contain environmentally hazardous materials, the disposal of which is strictly regulated by various governmental agencies, such as the Environmental Protection Agency. These hazardous materials must be placed in special containers before being properly disposed of by a government-approved waste disposal company.
The cost of disposing of these hazardous material containers is relatively expensive and thus it is undesirable to place an entire material cartridge in the containers if the chambers of the containers do not contain any of the hazardous material. It would be advantageous to simply remove the nozzle and valve which contain the hazardous material and which would occupy a lot less space in the disposal container thus reducing the amount of wasted space in the hazardous material container previously occupied by the empty material cartridges.
Further, by forming the valve integrally with the material cartridge, the packaging and shipping size of the material cartridge is increased substantially. The length of the shipping container must be extended beyond the length of the valve member and nozzle, thus increasing both the packaging and shipping costs. The add-on valve assembly of the present invention would reduce the length of the shipping container requiring the container to have a length only slightly longer than the cylindrical body of the material cartridge. The valve assembly could be sold as a separate unit. Depending on the type of materials being dispensed by the material cartridge, the valve assembly could be cleaned and re-used on new material cartridges.
Therefore, the need exists for an improved add-on valve assembly for dual-component cartridges which is removably secured to a nozzle of the cartridge, which can be removed from the cartridge allowing the valve assembly and the materials which remain in the valve assembly to be cleaned therefrom or properly discarded and which reduces the size of the packaging and shipping container of the material cartridge.